"You can NOT be serious," he famously shouted in Wimbledon in 1981 when one of his serves was called out.

McEnroe's words became a catchphrase to bait umpires and line judges around the world.

But more than a quarter of a century later, match officials have their comeuppance.

The study analysed 1473 challenges to line calls by 246 professional tennis players in 2006 and 2007.

The study compared the line judge's call and the player's challenge with the final word from Hawk-Eye, a ball-tracking system used by the Association of Tennis Professionals that can spot the position of a ball in play to within 3 millimetres.

Professional players and line judges "are remarkably proficient" at judging ball bounce position, the researchers show.

They display an accuracy to within just a few centimetres when the ball is travelling at 50 metres per second, says author Professor George Mather, a University of Sussex psychologist.

But the line judges are more reliable than the players. According to Mather's calculations, the judge is right 61% of the time when challenged.

This accuracy is good enough to silence those demanding that players should be allowed more than the current maximum of two unsuccessful challenges per set, the study says.

Errors near court line

Mather found most erroneous calls happen when a ball bounces within 100 millimetres of a court line, which line judges wrongly call nearly one time in 12.

And, says Mather, these miscalls are far likelier when the ball bounces near the base and service lines rather than near the side and centre lines.

One reason for this could be that base/service line judges sit much closer to the line than the side/centre judges, a distance of about 5.5 metres as opposed to 8.7 metres.

As a result, the image of the ball may pass too fast across the retina for the brain to get a precise fix on the ball's immediate position, a phenomenon called retinal motion bias.

The bias may particular affect balls hit down the centre of the court rather than diagonally. Such balls travel much faster across the judge's field of view.

"Training and line judge selection should focus on maximising performance for base and service line calls, since these are the most error-prone," the paper says.